1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device including a spacer to maintain a cell gap, and a method of manufacturing the same.
2. Discussion of the Related Art
Among various ultra-thin flat type display devices, which include a display screen having a thickness of several centimeters (cm), an LCD device has been widely used for notebook computers, monitors and aircrafts owing to the advantageous properties of low power consumption and portability.
In case of the small-sized LCD device, a cell gap of the LCD device is maintained only by a sealant to bond the two substrates of the LCD device. However, as the LCD device increases in size, it is difficult to maintain the constant cell gap formed in the central portion of the panel by the sealant formed in the edge of the panel. In this respect, the large-sized LCD device necessarily requires an additional spacer to maintain the constant cell gap.
Hereinafter, a method of forming a spacer in a related art LCD device will be explained with reference to the accompanying drawings.
FIG. 1 is a perspective view of a related art method of forming a ball spacer in a process of manufacturing an LCD device.
Referring to FIG. 1, a spraying nozzle 30 is positioned above a substrate 20 which is loaded on a stage 10. Then, ball spacers 40 are sprayed on the entire surface of substrate 20 through the spraying nozzle 30. Also, a sealant 50 is formed in the edge of substrate 20.
The process of forming the ball spacer 40 includes either a wet spray method or a drying spray method on the basis whether the ball spacers 40 sprayed through the spraying nozzle 30 are mixed with solvent or gas.
In the wet spray method, the ball spacers 40 mixed with the solvent are sprayed on the substrate 20. This method has the advantage in that the ball spacers 40 are sprayed on the substrate 40 evenly. However, the ball spacers 40 lump easily in the process of mixing the ball spacers 40 with the solvent.
In the drying spray method, the ball spacers 40 mixed with nitrogen gas (N2) are sprayed on the substrate 20. This method has the advantage in that the ball spacers are not lumped easily. In the drying spray method, however, it is difficult to evenly spray the ball spacers 40 on the entire surface of substrate 20.
For the both wet and drying spray methods, the ball spacers 40 are sprayed on the entire surface of substrate 20. As the ball spacers 40 are sprayed, the ball spacers 40 are irregularly arranged on the substrate 20. Also, the ball spacers 40 may be sprayed on pixel regions, whereby the picture quality is degraded.
In order to address this limitation where the picture quality is degraded, a method of forming a column spacer in non-pixel regions has been proposed. The process of forming the column spacer uses a photolithography.
Since the column spacers are formed in the non-pixel regions, it is possible to prevent the picture quality from being degraded. However, the photolithography requires a high-priced mask and exposure apparatus, whereby the manufacturing cost is increased. Further, after forming the column spacers, it is necessary to inspect whether the column spacers have the constant height.